Amphiregulin-associated protein: complete amino acid sequence of a protein produced by the 12-0-tetradecanoylphorbol-13-acetate-treated human breast adenocarcinoma cell line MCF-7

Abstract

Amphiregulin-associated protein (ARAP) was purified from serum-free conditioned medium of MCF-7, human breast carcinoma cells, treated with 12-0-tetradecanoylphorbol-13-acetate (TPA). ARAP is a single-chain, extremely hydrophilic, heparin-binding protein. Its apparent molecular weight is approximately 21,500 as assessed by gel chromatography and approximately 15,500 as determined by polyacrylamide gel electrophoresis. The complete amino acid sequence of ARAP was determined. The larger form contains 123 amino acids, whereas a shorter form is missing two amino acids at the amino-terminal. ARAP contains 10 cysteines and 30 basic amino acids (23 lysines and 7 arginines). ARP sequence has been found to be identical to protein encoded by human MK gene.